Infectious diseases are a common complication of illicit drug use. But the routes of transmission and variety of infectious microbes to which drug abusers are vulnerable may be more wide-ranging than many physicians realize.
A recent review details the roles that certain drugs, contaminated paraphernalia, additives, and drug users' own commensal flora play in disease transmission (Kaushik KS et al. J Med Microbiol. 10.1099/jmm.0.027540-0 [published online ahead of print March 9, 2011]).
Voelker R. Illicit Drug Use Creates Opportunities for Microbes. JAMA. 2011;305(13):1289. doi:10.1001/jama.2011.379